Toshiba made 8 different Tecra 8000 models. Go here and select your model from the drop-down menus.
Toshiba Canada driver page:
I believe this model contains the NeoMagic NM2200 Display adapter which is not supported by Toshiba in Windows XP. They only list drivers for 9x and NT. You can try the NT driver but I won't guarantee it will work in XP.